Golf Club Head

ABSTRACT

A golf club head designed to act under impact load as a bridge comprising a face; an inertial support system; a rear structure; and a force transfer system, under impact load the force transfer system, in cooperation with the inertial support system, elongating the rear structure and controlling the bending of the face, the pattern of bending of the face being a substantially bridge-like pattern of bending or a substantially modified bridge-like pattern of bending.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/972,479 filed on Dec. 19, 2010, which is a continuation of U.S.patent application Ser. No. 11/246,561 filed on Oct. 7, 2005, now U.S.Pat. No. 7,854,665 issued Dec. 21, 2010, which is a continuation ofPCT/US2004/023368 filed on Jul. 22, 2004, and a continuation-in-part ofPCT/US2003/11085 filed on Apr. 11, 2003, the disclosures of which, intheir entireties, are incorporated herein by reference.

TECHNICAL FIELD AND BACKGROUND ART

The present invention relates to golf club heads and, more particularly,to the design of golf club heads.

In general, golf club heads are designed as either solid bodies (forexample, persimmons), plates (for example, irons and putters withperimeter weights), or shells with a diaphragm face (for example, metaldrivers and fairway woods). Today, the general consensus is that a shellwith a diaphragm face provides the optimal design solution for a golfclub head, with incremental improvements on that design helping toimprove how far and how accurately a golfer can hit the golf ball.

For example, as discussed in U.S. Pat. No. 6,348,015, the face of a“shell” golf club head is designed from a material having a naturalfrequency between 2800 Hz and 4500 Hz. Upon hitting the material, thegolf ball undergoes smaller deformations and, hence, lower energylosses. Or, as discussed in U.S. Pat. No. 6,348,013, a “shell” golf clubhead is designed with one or more recesses in one or more of the head'swalls. The recesses increase the amount of time the face of the headremains in contact with the ball, again reducing energy loss.

Similarly, in U.S. Pat. No. 6,267,691, the face of a “shell” golf clubis reinforced with parallel ribs along the back side of the face,controlling how the face bends under impact load. The ribs help resistbending of the face in a direction parallel to the ribs, but permitbending of the face in a direction perpendicular to the ribs. Thereinforcing ribs help dampen the head's vibrations and give the face alarger region in which there is an efficient transfer of energy from theface to the ball (known as the “sweet spot”).

SUMMARY OF THE INVENTION

In accordance with one aspect of the invention, a golf club headcomprises a face, an inertial support system, a rear structure, and aforce transfer system. Under impact load, the force transfer systemelongates the rear structure and controls, in cooperation with theinertial support system, the bending of the face, the pattern of bendingof the face being a substantially bridge-like, or substantially modifiedbridge-like, pattern of bending.

In a further embodiment of the invention, the rear structure cooperateswith the force transfer system and the inertial support system incontrolling the bending of the face, the pattern of bending of the facebeing a substantially bridge-like, or a substantially modifiedbridge-like, pattern of bending. In another further embodiment of theinvention, during an off-center impact load, a part of the face movesforward relative to the inertial support system. In an additionalembodiment of the invention, the force transfer system and the rearstructure control the forward movement of the face.

In still another embodiment of the invention, the golf club head furthercomprises a torsion control system, which is operatively connected tothe inertial support system. The torsion control system may comprise across-brace, an insert, some combination of a cross-brace and an insert,or some combination of a cross-brace and a portion of an insert. Theinsert may have a wall thickness that is constant, multiple, varying orprofiled. In addition, the torsion control system may be re-configurableor replaceable.

In alternate embodiments of the invention, the inertial support systemmay include a hosel, and the mass of the inertial support system may beat least equal to the combined mass of the face, the force transfersystem and the rear structure. Also, the inertial support system, theforce transfer system, the face, the rear structure or the torsioncontrol system may each be an integral unit, or some combination of theinertial support system, the force transfer system, the face, the rearstructure or the torsion control system may be an integral unit. Inaddition, the force transfer system may be separated into one or moreportions.

In further embodiments of the invention, the force transfer system maybe the crown of the golf club head, the sole of the golf club head, or acombination of the crown and sole of the golf club head. Or, a part ofthe force transfer system may be the crown of the golf club head, thesole of the golf club head, or a combination of the crown and sole ofthe golf club head. In addition, the golf club head may include aconventional crown or a conventional sole. The conventional crown orconventional sole may be composed of a thermoset elastomer, athermoplastic elastomer, or an engineering plastic. The thermosetelastomer, thermoplastic elastomer, or engineering plastic may becombined with fillers or fibers, such as glass or carbon, to form acomposite structure. Also, the conventional crown or conventional solemay be transparent (in whole or in part) or translucent (in whole or inpart).

In accordance with another aspect of the invention, a golf club headcomprises a face and a substantially non-deforming mass connected to theface. Under impact load, the contact forces from the impact load, inconnection with the resulting inertial reaction forces from thesubstantially non-deforming mass produce a pattern of bending of theface that is a substantially bridge-like, or substantially modifiedbridge-like, pattern of bending.

In accordance with still another aspect of the invention, a golf clubhead comprises a face, an inertial support system, a rear structure, anda force transfer system. Under on-center impact load, the force transfersystem may be placed in a state of substantially pure axial compression.

In a further embodiment of the invention, the rear structure may beplaced in a state of substantially pure axial tension under on-centerimpact load.

In accordance with a further aspect of the invention, a golf club headdesigned to act under impact load as a bridge comprises a face, the faceacting as a bridge span; an inertial support system, the inertialsupport system acting as a bridge support; a rear structure and a forcetransfer system, the force transfer system and the rear structure actingtogether as a bridge truss.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing features of the invention will be more readily understoodby reference to the following detailed description, taken with referenceto the accompanying drawings, in which:

FIG. 1 is a schematic top view of an exemplary embodiment of a golf clubhead designed to act, under impact load, as a bridge.

FIG. 2 is a schematic top view of an exemplary embodiment of a golf clubhead designed to act, under impact load, as a bridge.

FIG. 3 is a schematic top view of an exemplary embodiment of a golf clubhead designed to act, under impact load, as a bridge.

FIG. 4 is a schematic top view of an exemplary embodiment of a golf clubhead designed to act, under impact load, as a bridge.

FIG. 5 is a schematic top view of an exemplary embodiment of a golf clubhead designed to act, under impact load, as a bridge.

FIG. 6 is a schematic side view of an exemplary embodiment of a golfclub head designed to act, under impact load, as a bridge.

FIG. 7 a is a schematic top view, and FIG. 7 b is a sectional view, ofan exemplary embodiment of a golf club head designed to act, underimpact load, as a bridge.

FIG. 8 is a schematic top view of an exemplary embodiment of a golf clubhead with an exemplary embodiment of a torsion control system, the golfclub head designed to act, under impact load, as a bridge.

FIG. 9 is a schematic top view of an exemplary embodiment of a golf clubhead with an exemplary embodiment of a torsion control system, the golfclub head designed to act, under impact load, as a bridge.

FIG. 10 is a schematic top view of an exemplary embodiment of a golfclub head with an exemplary embodiment of a torsion control system, thegolf club head designed to act, under impact load, as a bridge.

FIG. 11 a and FIG. 11 b are schematic side views of an exemplaryembodiment for a torsion control system used in a golf club headdesigned to act, under impact load, as a bridge.

FIG. 12 a and FIG. 12 b are graphs showing the pattern of bending ingolf club heads according to embodiments of the invention in comparisonto diaphragm golf club heads.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

In accordance with one embodiment of the invention, a golf club head isdesigned to act as a “bridge” when the golf club head impacts a golfball during game play (referred to hereinafter as “under impact load”).In general, the face of the golf club head corresponds to the bridgespan, with the bridge truss and the bridge inertial supports locatedbehind the face. As such, the bridge-like golf club head designsdescribed herein are minimum weight structures that areinertially-supported under dynamic loading.

For ease of reference, the term “bridge” is used herein to refer to botha bridge structure and a modified bridge structure. In a bridgestructure, most, if not all, of the characteristics of the structure aresimilar to the characteristics of a bridge—with few, if any, of thecharacteristics of other structures, such as a solid body, a plate, or ashell with a diaphragm face. In a modified bridge structure, some, butnot all, of the characteristics of the structure are similar to thecharacteristics of a bridge—with additional characteristics of otherstructures, such as a solid body, a plate, or a shell with a diaphragmface.

In general, a golf club head designed to act, under impact load, as abridge may have a sweet spot that extends across the height of the faceof the golf club head and a center of mass that may be closer to theface of the golf club head. The bridge truss, located behind the face,may be tailored to provide a particular rate of deflection under impactload, and the bridge inertial supports may be tailored to provide aparticular moment of inertia. Furthermore, the mass of the golf clubhead needed to support the impact load may be less than the mass neededin a “shell” golf club head. This leaves more mass available to optimizethe inertial performance of the golf club head.

FIG. 1 is a schematic of an exemplary embodiment of a golf club headdesigned to act, under impact load, as a bridge. In golf club head 100,face 110 is connected to inertial support system 120 and force transfersystem 130. In turn, rear structure 140 is connected to force transfersystem 130 and face 110. Force transfer system 130 comprises twocomponent parts, inner structure 130 a and radial structure 130 b.

For ease of reference, the term “connection” is used herein to refer tophysical connections between structures, as well as operationalconnections between structures. For example, the statement thatstructure A is connected to structure B may mean: (1) structure A isphysically attached to structure B; (2) structure A interacts withstructure B under operational conditions; or (3) structure A isphysically attached to structure B and structure A interacts withstructure B under operational conditions.

Inertial support system 120, connected to the left side edge and rightside edge of face 110, provides support for the “bridge structure” ofgolf club head 100. The bridge structure is that part of golf club head100 required to support the impact load of a golf ball—face 110, forcetransfer system 130 and rear structure 140. Under impact load, thebridge structure transfers load to inertial support system 120.

Under an off-center impact load, inertial support system 120 alsoopposes the “rotation” of golf club head 100 resulting from theoff-center impact load. For example, when a golf club head hits a golfball somewhere between the center of the face and the toe of the golfclub head, the golf club head will rotate about a vertical axis. Inturn, the golf ball will travel in an unintended direction. Withopposition, such as that provided with inertial support system 120, therotation of the golf club head is reduced. In other words, inertialsupport system 120 produces high moments of inertia for golf club head100.

In general, under impact load, force transfer system 130, in connectionwith inertial support system 120, elongates rear structure 140, controlsthe “bending” of face 110 (and thus the deflection of face 110), andcontrols the rate of deflection of face 110. For example, force transfersystem 130 and inertial support system 120 may control the rate ofdeflection of face 110 at the same rate of deflection of a golf ball hitat a particular swing velocity, thereby achieving a good dynamicresponse and an impedance match between face 110 and the golf ball. Ingolfer parlance, a good impedance match means a good driving distancefor the golf ball. In an alternate embodiment of golf club head 100,rear structure 140 may also, in connection with force transfer system130 and inertial support system 120, control the bending of face 110 andcontrol the rate of deflection of face 110.

In addition, under an on-center impact load, with force transfer system130 and rear structure 140 acting substantially in the manner of abridge truss, force transfer system 130 and rear structure 140 areplaced in a state of either substantial axial compression or substantialaxial tension. In particular, inner structure 130 a and radial structure130 b are placed in a state of substantial axial compression (a “push”along the length of a structure) and rear structure 140 is placed in astate of substantial axial tension (a “pull” along the length of astructure).

Under all impact loads, on-center and off-center, face 110 bends underthe impact. As shown in FIG. 12 a, however, the pattern of bendingdiffers from the pattern of bending seen in the face of a “drum” golfclub head. In a drum golf club head, also referred to herein as adiaphragm golf club head, the pattern of bending of the face as measuredalong a vertical line (in relation to the horizon) from the top edge ofthe face to the bottom edge of the face is not uniform. In other words,along a vertical line A₀ to A₁₀, the rearward deflection of A₀ may notequal the rearward deflection of A₁, the rearward deflection of A₁ maynot equal the rearward deflection of A₂, the rearward deflection of A₂may not equal the rearward deflection of A₃, etc. The reason for thenon-uniform bending is inherent in the diaphragm golf club head'sdesign, which requires rigid connections of the face along its top,bottom and side edges.

In golf club head 100, the pattern of bending of face 110 issubstantially uniform from the top edge of the face to the bottom edgeof the face, as measured along a vertical line (in relation to thehorizon) (hereinafter referred to as “bridge-like pattern of bending”).In other words, along a vertical line B₀ to B₁₀, the rearward deflectionof B₀ is substantially equal to the rearward deflection of B₁, therearward deflection of B₁ is substantially equal to the rearwarddeflection of B₂, the rearward deflection of B₂ is substantially equalto the rearward deflection of B₃, etc. Thus, in comparison to adiaphragm golf club head, which has a sweet “spot” (defined as a singlepoint on the face of the diaphragm golf club head), face 110 has a sweet“line” (defined as a series of points on face 110 of golf club head100). The “sweet” region on the face of a golf club head is, in part,the region optimized to have efficient transfer of energy from the faceof the golf club head to the golf ball.

A person of skill in the art understands that the phrase “along avertical line (in relation to the horizon)” is used for ease ofreference. In operation, in many golf club heads, the vertical axis ofthe club face may not be perpendicular to the horizon. Instead, thevertical axis of the club face may be angled in relation to the horizon(for example, oriented in relation to a particular “hit” distribution).Thus, in such a club face, the bridge-like pattern of bending may occuralong a line substantially parallel to the vertical axis of the clubface. In addition, in many golf club heads, the face of the golf clubhead may not be planar (for example, the face may have a roll). In sucha club face, the bridge-like pattern of bending may occur along a linesubstantially tangential to the curved face of the golf club head. Inother words, a bridge-like pattern of bending is a pattern of bending offace 110 that is substantially uniform from near the top edge of face110 to near the bottom edge of face 110, as measured along a verticalline (in relation to the horizon), as measured along a linesubstantially parallel to the vertical axis of face 110 (which may notbe perpendicular to the horizon) or as measured along a linesubstantially tangential to a curve in face 110.

In an alternate embodiment of golf club head 100, the pattern of bendingof face 110 is a “modified” bridge-like pattern of bending. In amodified bridge-like pattern of bending the maximum deflections (andrates of deflection) at various points of impact for various impacts,which occur over a substantial area of the face, have approximately thesame value. In other words, in an area C of the face, the rearwarddeflection Z₁ from impact I₁ (which occurs at point [X₁, Y₁] on theface) is substantially equal to the rearward deflection Z₂ from impactI₂ (which occurs at point [X₂, Y₂] on the face), the rearward deflectionZ₂ from impact I₂ is substantially equal to the rearward deflection Z₃from impact I₃ (which occurs at point [X₃, Y₃] on the face), therearward deflection Z₃ from impact I₃ is substantially equal to therearward deflection Z₄ of impact I₄ (which occurs at point [X₄, Y₄] onthe face), etc. Thus, despite the fact that impacts I₁, I₂, I₃ and I₄are all at different points on face 110, the deflections from theimpacts are substantially equal, such that Z₁≈Z₂≈Z₃≈Z₄ . . . ≈Z_(n). Inaddition, the rates of deflections from the impacts are alsosubstantially equal, such that Ż₁≈Ż₂≈Ż₃≈Ż₄ . . . ≈Ż_(n).

In contrast, as shown in FIG. 12 b, in a diaphragm golf club head, themaximum deflections (and rates of deflection) at various points ofimpact for various impacts, which occur over a substantial area of theface, do not have approximately the same value. In other words, in anarea D on the face, the rearward deflection Z₁ from impact I₁ (whichoccurs at point [X₁ Y₁] on the face) is not substantially equal to therearward deflection Z₂ from impact I₂ (which occurs at point [X₂, Y₂] onthe face), the rearward deflection Z₂ from impact I₂ is notsubstantially equal to the rearward deflection Z₃ from impact I₃ (whichoccurs at point [X₃, Y₃] on the face), the rearward deflection Z₃ fromimpact I₃ is not substantially equal to the rearward deflection Z₄ ofimpact I₄ (which occurs at point [X₄, Y₄] on the face), etc. Thus, in adiaphragm golf club head, the deflections from the impacts are notsubstantially equal, such that Z₁

Z₂

Z₃

Z₄ . . .

Z_(n). In addition, the rates of deflection from the impacts are alsonot substantially equal, such that Ż₁

Ż₂

Ż₃

Ż₄ . . .

Ż_(n).

In one embodiment of the invention, the “sweet” area of face 110 is morethan approximately 25% of the area of face 110. In all embodiments forthe sweet regions (both lines and areas) of face 110, the regions may beangled to better match the golf impact distribution for a particulargolfer (or a group of golfers). For example, the sweet regions of face110 may be angled at 30° from the horizontal.

As discussed, under an off-center impact load, face 110 bends with thebridge-like pattern of bending. In addition, during an off-center impactload, a part of face 110 moves forward relative to inertial supportsystem 120. Typically, the part of face 110 that moves forward relativeto inertial support system 120 is opposite from the side of face 110impacted by the golf ball. It is believed that the forward movement offace 110 under an off-center impact load, which the force transfersystem and the rear structure control, accounts for one of the greatcharacteristics of a bridge-like golf club head—the ability to drive thegolf ball in its intended direction even though the golfer hit the golfball off the center line of face 110.

In an alternate embodiment of golf club head 100, face 110 includes a“hinged” portion (or portions) that flex(es), acting as a hinge. Thehinged portion, typically located to the right side edge or left sideedge of face 110, flexes under impact load. In other words, the hingedportion of face 110 rotates about the connection of face 110 andinertial support system 120.

In a further alternate embodiment of golf club head 100, the mass ofinertial support system 120 is greater than, or equal to, the combinedmass of face 110, force transfer system 130 and rear structure 140.Thus, in this alternate embodiment of golf club head 100, at least 50%of the mass of golf club head 100 may be used to optimize moment ofinertia values for golf club head 100.

In still further alternate embodiments of golf club head 100, face 110may not be physically connected to inertial support system 120 (seecorresponding golf club elements in FIG. 5) or face 110 may not bephysically connected to rear structure 140 (not shown). However, underimpact load, these alternate embodiments of golf club head 100 react thesame as golf club head 100. For example, inertial support system 120provides support for the bridge structure of golf club head 100,receiving the load during impact and, under off-center impact loads,opposing rotation of golf club head 100. In addition, in connection withother systems, force transfer system 130 controls the bending of face110 (and thus the deflection of face 110) and controls the rate ofdeflection of face 110.

FIG. 2 is a schematic of an exemplary embodiment of a golf club headdesigned to act, under impact load, as a bridge. In golf club head 200,force transfer system 230 comprises three radial structures, notated as230 b, rather than one radial structure. Under impact load, radialstructures 230 b react in the same manner as radial structure 130 b. Inother words, under an on-center impact load, radial structures 230 b areeach placed in a state of substantially pure axial compression,exhibiting minimal bending. While the disclosed exemplary embodimentsdescribe a force transfer system with either one radial structure orthree radial structures, the force transfer system may comprise anynumber of radial structures. For example, the force transfer system mayappear to the naked eye to be a “solid” structure but, on a microscopiclevel, is comprised of some number of radial structures. A person ofskill in the art understands that, as the number of radial structuresincreases, the more closely the force transfer system approximates aminimum weight structure.

FIG. 3 is a schematic of an exemplary embodiment of a golf club headdesigned to act, under impact load, as a bridge. In golf club head 300,face 310 is connected to inertial support system 320, force transfersystem 330, and back 350. In turn, rear structure 340 is connected toforce transfer system 330 and face 310. Force transfer system 330comprises two component parts, inner structure 330 a and radialstructure 330 b.

However, unlike the inertial support systems for golf club head 100 and200, the inertial support system for golf club head 300 is a set ofconcentrated mass elements (hereinafter referred to as “posts”). Underimpact load, inertial support system 320 reacts in the same manner asinertial support systems 120 and 220—providing support for the bridgestructure of golf club head 300, receiving the load during impact and,under off-center impact loads, opposing rotation of golf club head 300.

In an alternate embodiment of golf club head 300, inertial supportsystem 320 is comprised of a set of posts connected with one or morebars. The bars may connect the posts along any point, or points, on theposts. For example, the bars may connect just the top of the posts, justthe bottom of the posts, just the center of the posts, or both the topand the bottom of the posts.

FIG. 4 is a schematic of an exemplary embodiment of a golf club headdesigned to act, under impact load, as a bridge. In golf club head 400,face 410 is connected to inertial support system 420 (which includeshosel 450) and force transfer system 430. In turn, rear structure 440 isconnected to force transfer system 430 and face 410. In this exemplarygolf club head, the connection between face 410 and inertial supportsystem 420 is line connection A, which is substantially perpendicular tothe page. A line connection is a connection between two structures alonga single set of points substantially forming a line. Force transfersystem 430 comprises three component parts, inner structure 430 a andradial structures 430 b.

As shown in FIG. 4, inertial support system 420 is a set of posts,notated as 420 a, connected with a curved bar, notated as 420 b.Inertial support system 420 may straddle radial structures 430 b, mayrest on top of radial structures 430 b, or may rest within radialstructures 430 b. Under impact load, inertial support system 420 reactsin the same manner as inertial support systems 120, 220 and320—providing support for the bridge structure of golf club head 400,receiving the load during impact and, under off-center impact loads,opposing rotation of golf club head 400.

FIG. 5 is a schematic of an exemplary embodiment of a golf club headdesigned to act, under impact load, as a bridge. As noted above, in FIG.5, face 510 is not physically connected to inertial support system 520.

FIG. 6 is a schematic of an exemplary embodiment of a golf club headdesigned to act, under impact load, as a bridge. Like golf club head500, face 610 is connected to force transfer system 630 and rearstructure 640, but is not physically connected to inertial supportsystem 620. Force transfer system 630 comprises eight component parts,inner structures 630 a and radial structures 630 b.

In addition, force transfer system 630 is separated into a top portionand a bottom portion. The separation may occur at any point along theheight of force transfer system 630, with the height of the top portionbeing equal to, less than, or greater than, the height of the bottomportion. Under impact load, golf club head 600 reacts the same as golfclub heads 100 through 500. In particular, force transfer system 630produces the same effect produced in force transfer systems 130 through530—that is, in connection with inertial support system 620 (or, in analternate embodiment, in connection with inertial support system 620 andrear structure 640), elongating rear structure 640, controlling thebending of face 610 (and thus the deflection of face 610), andcontrolling the rate of deflection of face 610.

In alternate embodiments of golf club head 600, force transfer system630 may be separated into a left portion and a right portion. Theseparation may occur at any point along the length of force transfersystem 630, with the length of the left portion being equal to, lessthan, or greater than, the length of the right portion. In addition,force transfer system 630 may be separated into more than two portions,with the height (or length) of each portion being equal to, less than,or greater than the height (or length) of any other portion. Inaddition, the separate portions of force transfer system 630 may not be“mirror images” of each other. In other words, the separate portions offorce transfer system 630 may have different structures. For example, ina force transfer system with a top portion and a bottom portion, the topportion may be structured similar to force transfer system 430 (in FIG.4) and the bottom portion may be structured similar to force transfersystem 230 (in FIG. 2). Also, the separate portions of force transfersystem 630 may be “misaligned” with one or more of the separate portionsin a different plane than one or more of the other portions.

FIGS. 7 a and 7 b are schematics of an exemplary embodiment of a golfclub head designed to act, under impact load, as a bridge. In golf clubhead 700, face 710 connects to inertial support system 720 and forcetransfer system 730. In turn, rear structure 740 is connected to forcetransfer system 730 and face 710.

Unlike force transfer systems 130 through 630, force transfer system 730comprises the crown of golf club head 700. In particular, force transfersystem 730 is a crown of varying thickness that acts as part of thebridge structure. For example, as shown in FIG. 7 b, force transfersystem 730 may have a single region, in which the thickness varies fromthe front of the region to the back of the region. Or, force transfersystem 730 may have more than one region, in which the thickness of eachregion varies in the same manner or in different manners. For example,in each region the thickness may vary from the front of each region tothe back of each region. Or, in a first region, the thickness may varyfrom the front of that region to the back of that region, in a secondregion, the thickness may vary from the center of that region to theedges of that region, etc. Under impact load, force transfer system 730produces the same effect produced in force transfer systems 130 through630—that is, in connection with inertial support system 720 (or, in analternate embodiment, in connection with inertial support system 720 andrear structure 740), elongating rear structure 740, controlling thebending of face 710 (and thus the deflection of face 710), andcontrolling the rate of deflection of face 710.

In an alternate embodiment of golf club head 700, force transfer system730 comprises the sole of golf club head 700. In another alternateembodiment of golf club head 700, force transfer system 730 comprisesboth the crown and the sole of golf club head 700.

In another alternate embodiment of golf club head 700, force transfersystem 730 may comprise a part of the crown of golf club head 700, theremaining part of force transfer system configured in a manner similarto the force transfer systems shown in FIGS. 1-6. Or, force transfersystem 730 may comprise a part of the sole of golf club head 700, theremaining part of force transfer system configured in a manner similarto the force transfer systems shown in FIGS. 1-6. Likewise, forcetransfer system 730 may comprise a part of the crown and a part of thesole of golf club head 700, the remaining part of force transfer systemconfigured in a manner similar to the force transfer systems shown inFIGS. 1-6.

FIG. 8 is a schematic of an exemplary embodiment of a golf club headdesigned to act, under impact load, as a bridge. In golf club head 800(which is similar in structure to golf club head 100), a torsion controlsystem, identified as cross-brace 850, is connected to rear structure840 and force transfer system 830. Under off-center impact load,cross-brace 850 provides torsional resistance to force transfer system830. In other words, in connection with inertial support system 820,cross-brace 850 opposes the internal “rotation” (relative to inertialsupport system 820) of force transfer system 830 resulting from anoff-center impact load. In addition, in an off-center impact load,approximately one-half (left side or right side) of cross-brace 850 isplaced in a state of substantially pure axial compression andapproximately one-half (right side or left side) is placed in a state ofsubstantially pure axial tension.

In an alternate embodiment of golf club head 800, the mass of inertialsupport system 820 is no less than 30% of the combined mass of face 810,force transfer system 830, rear structure 840 and torsion control system850. Thus, in this alternate embodiment of golf club head 800, a largeportion of the mass of golf club head 800 may be used to optimize momentof inertia values for golf club head 800.

FIG. 9 is a schematic of an exemplary embodiment of a golf club headdesigned to act, under impact load, as a bridge. In golf club head 900(which is similar in structure to golf club head 200), a torsion controlsystem, identified as cross-brace 950, is connected between the variousapproximate intersections of rear structure 940, and/or inner structure930 a, and/or radial structure 930 b, and/or face 910. Like cross-brace850, cross-brace 950 provides torsional resistance to force transfersystem 930. In other words, in connection with inertial support system920, cross-brace 950 opposes the internal “rotation” (relative toinertial support system 920) of force transfer system 930 resulting froman off-center impact load.

FIG. 10 is a schematic of an exemplary embodiment of a golf club headdesigned to act, under impact load, as a bridge. In golf club head 1000(which is similar in structure to golf club head 500), a torsion controlsystem, identified as insert 1050, is placed in the “opening” betweenforce transfer system 1030 and rear structure 1040 and/or in the“opening” between force transfer system 1030, rear structure 1040 andface 1010, and/or in the “opening” between force transfer system 1030and face 1010. As shown in FIG. 11 a, insert 1050 is a “cored out”structure that comprises two component parts, web 1052 and flange 1054.In contrast, insert 1050 may be a solid structure (not shown). In analternate embodiment, as shown in FIG. 11 b, insert 1050 may furthercomprise a cross-brace, such as cross-brace 1056. Insert 1050 may alsocomprise a flange, such as flange 1054, and a cross-brace, such ascross-brace 1056. Insert 1050 may be composed of an assembly of multipleelements, the elements composed of metal, plastic or compositematerials. Insert 1050 may also be composed, in whole or in part, offoam.

In addition, web 1052 may have constant wall thicknesses, multiple wallthicknesses, varying wall thicknesses or profiled wall thicknesses. Forexample, the inner edge of web 1052 (near inner structure 1030 a) may bethicker than the outer edge of web 1052 (near rear structure 1040 orinertial support system 1020). In another alternate embodiment, thethickness of web 1052 may mirror the thickness of radial structure 1030b. It may also be profiled to conform with the deformation of radialstructure 1030 b under center impact loading.

Like cross-braces 850 and 950, insert 1050 provides torsional resistanceto force transfer system 1030. Thus, in connection with inertial supportsystem 1020, insert 1050 opposes the internal “rotation” (relative toinertial support system 1020) of force transfer system 1030 resultingfrom an off-center impact load.

In tuning performance of the golf club head, the torsion control system(whether a cross-brace, an insert, or some combination of both) may bepositioned at any point along the height of the force transfer system.In addition, the torsion control system may be positioned at differentpoints along the height of the force transfer system for each “opening”in the golf club head. Further, one or more “openings” in the golf clubhead may contain more than one component of the torsion control systemor, in the alternative, contain no component of the torsion controlsystem. A person of skill in the art understands that tuning the torsioncontrol system “tunes” the rate of deflection of the face and, in turn,the impedance match between the face of the golf club head and the ball.

The geometry and/or material property and/or attachment method of thetorsion control system may also be varied to tune the performance of thegolf club head. The performance tuning may occur at the time ofmanufacture, at the time of sale, or “in the field”—making the torsioncontrol system re-configurable and/or replaceable. These “sets” oftorsion control systems may be designed for the needs of a particulargroup of golfers or for the needs of a particular golfer.

In an alternate embodiment of each of the exemplary embodiments of golfclub heads, the golf club heads may further include a back, such as back350 in golf club head 300. Or, in further alternative embodiments ofeach of the golf club heads, the back of the golf club head may be therear structure or the inertial support system. In addition, the torsioncontrol system may form all (or part) of the sole or crown of the golfclub head. When forming all (or part) of the sole or crown of the golfclub head, the torsion control system may be composed (in whole or part)of a material that provides scuff resistance for the golf club head,such as a plastic, metal (for example, thin titanium) or compositematerial (such as a combination of metal and plastic).

In other alternate embodiments of each of the exemplary embodiments ofgolf club heads, the face may be convex in shape from crown to sole (forexample, a “roll”) or convex in shape from heel to toe (for example, a“bulge”) or convex in shape from crown to sole and heel to toe (forexample, a combination of a “roll” and a “bulge”).

In a further alternate embodiment of each of the exemplary embodimentsof golf club heads, the inertial support system further includes ahosel, such as hosel 450 in golf club head 400. A hosel is a connectionpoint on a golf club head to which a golf club shaft is attached. Inaddition, the golf club heads may include other “conventional” designoptions, such as offsets, face angles, loft angles or lie angles.

In still another embodiment of each of the exemplary embodiments of golfclub heads, the face, the inertial support system, the force transfersystem, the rear structure, and the torsion control system may beintegral units alone or in combination with each other. For example, theface and the force transfer system may be an integral unit, the inertialsupport system may be an integral unit, the face, the force transfersystem and the rear structure may be an integral unit, or the torsioncontrol system, the inertial support system and the force transfersystem may be an integral unit.

In a further embodiment of each of the exemplary embodiments of golfclub heads, the golf club head may further include a conventional crown,a conventional sole, or a conventional crown and a conventional sole.The term “conventional” is used herein to differentiate from the “crownof varying thickness” described in FIG. 7. In order to ensure that aconventional crown or conventional sole do not negatively impact thebridge-like operation of the golf club heads described herein, theconventional crown or conventional sole may be composed of a thermosetelastomer, a thermoplastic elastomer, or an engineering resin. Thethermoset elastomer, thermoplastic elastomer, or engineering plastic maybe combined with fillers or fibers, such as glass or carbon, to form acomposite structure. In addition, the conventional crown or conventionalsole may be transparent (in whole or in part) or translucent (in wholeor in part).

Although various exemplary embodiments of the invention have beendisclosed, it should be apparent to those skilled in the art thatvarious changes and modifications can be made which will achieve some ofthe advantages of the invention without departing from the true scope ofthe invention. These and other obvious modifications are intended to becovered by the appended claims.

1. A golf club head comprising: a body defining a face in a frontsection, a crown, a sole, a toe section, a heel section, and a rearsection, the face having a front side and a back side; a substantiallypolygonal or substantially arch structure connected at its ends to theback side of the face at two or more points; a radial extending from thedistal side of the substantially polygonal or substantially archstructure to the rear section; and a torsion control structure locatedwithin the opening formed between the back side of the face, the rearsection of the club, and the inner edges of the radial.
 2. The golf clubhead according to claim 1 in which the torsion control structure is across-brace, an insert, a combination of a cross-brace and an insert, ora combination of a cross-brace and a portion of an insert.
 3. The golfclub head according to claim 3 in which the insert has a constant wallthickness, a varying wall thickness, or a profiled wall thickness. 4.The golf club head according to claim 1 in which the torsion controlstructure is reconfigurable or replaceable.
 5. The golf club headaccording to claim 1 in which a substantial area of the face is at least25% of the face.
 6. The golf club head according to claim 6 in which theat least 25% of the face is substantially centered between the toesection and the heel section with a height approximately equal to theheight of the front side of the face.
 7. The golf club head according toclaim 1 in which the substantially polygonal or substantially archstructure and the radial are separated into a top portion and a bottomportion.
 8. The golf club head according to claim 8 further comprising astrut connecting a top portion and a bottom portion of the separatedsubstantially polygonal or substantially arch structure, a top portionand a bottom portion of the separated radial, a top portion of theseparated substantially polygonal or substantially arch structure to abottom portion of the separated radial, or a bottom portion of theseparated substantially polygonal or substantially arch structure to abottom portion of the separated radial.
 9. A golf club head comprising:a body defining a face in a front section, a crown, a sole, a toesection, a heel section, and a rear section, the face having a frontside and a back side; a substantially polygonal or substantially archstructure connected at its ends to the back side of the face at two ormore points; a radial extending from the distal side of thesubstantially polygonal or substantially arch structure to the rearsection; a torsion control structure located within the opening formedbetween the back side of the face, the rear section of the club, and theinner edge of the radial; and under impact load the substantiallypolygonal or substantially arch structure, the radial, and the torsioncontrol structure controlling the bending of the face to provide a firstvalue of deflection in the center of the face and a second value ofdeflection in an area away from the center of the face, the second valueof deflection being greater than the first value of deflection.
 10. Thegolf club head according to claim 9 in which the torsion controlstructure is a cross-brace, an insert, a combination of a cross-braceand an insert, or a combination of a cross-brace and a portion of aninsert.
 11. The golf club head according to claim 10 in which the inserthas a constant wall thickness, a varying wall thickness, or a profiledwall thickness.
 12. The golf club head according to claim 9 in which thetorsion control structure is reconfigurable or replaceable.
 13. The golfclub head according to claim 9 in which a substantial area of the faceis at least 25% of the face.
 14. The golf club head according to claim13 in which the at least 25% of the face is substantially centeredbetween the toe section and the heel section with a height approximatelyequal to the height of the front side of the face.
 15. The golf clubhead according to claim 9 in which the substantially polygonal orsubstantially arch structure and the radial are separated into a topportion and a bottom portion.
 16. The golf club head according to claim15 further comprising a strut connecting a top portion and a bottomportion of the separated substantially polygonal or substantially archstructure, a top portion and a bottom portion of the separated radial, atop portion of the separated substantially polygonal or substantiallyarch structure to a bottom portion of the separated radial, or a bottomportion of the separated substantially polygonal or substantially archstructure to a bottom portion of the separated radial.
 17. The golf clubhead according to claim 1 in which, under impact load, the substantiallypolygonal or substantially arch structure, the radial, and the torsioncontrol structure control the bending of the face to provideapproximately the same value of deflection and rate of deflection over asubstantial area of the face.